267
FXUS61 KBTV 150541
AFDBTV

Area Forecast Discussion
National Weather Service Burlington VT
141 AM EDT Wed May 15 2024

.SYNOPSIS...
Showers and thunderstorms will wind down overnight tonight, but the
unsettled weather pattern will continue over the next few days.
Several rounds of showers are expected through the rest of the week,
with Friday having the best potential to remain mostly dry.
Temperatures will remain seasonable through the weekend as well,
with highs generally in the 60s and 70s and lows in the 40s and 50s.

&&

.NEAR TERM /THROUGH THURSDAY/...
As of 129 AM EDT Wednesday...Forecast remains on track so only
made minor changes to bring it up to date. RAP mesoanalysis
shows a frontal boundary draped across southern Essex county in
NY into Addison county, and this is where a thunderstorm is
located. Despite the relatively slow forward motion, flooding is
not a concern as rainfall rates are quite manageable. Expect
thunder chances to wane after midnight, with rainfall tapering
into isolated showers. Patchy fog could also develop across
northern NY and northern/central VT with the recent rainfall
and dew point depressions generally less than 5 degrees.

PREVIOUS DISCUSSION...Scattered showers with isolated
thunderstorms will continue through the rest of this afternoon
into the evening hours, especially from the Adirondacks eastward
into north- central/central VT. The main threat from this
activity will be briefly heavy rainfall. Given fairly
unidirectional flow and a slow moving frontal boundary just to
our north, training of cells will be a concern. Flooding is not
anticipated, but ponding of water in poor drainage areas will be
possible, especially in locations that see multiple
showers/storms. Otherwise, have already seen one or two more
robust thunderstorms this afternoon, with a couple of reports of
small hail. Strong winds will be possible in stronger storms,
as well. Strong storms will continue to be possible through 7 pm
or so, and while an isolated marginally severe thunderstorm
can`t be totally ruled out, the risk is low with widespread
severe not anticipated.

Showers and thunderstorms will wind down this evening as we lose
daytime heating and instability. The front will make a slow push
southward overnight, eventually hanging up somewhere over
northern/central portions of our forecast area. Moisture will linger
however, keeping plenty of clouds around. Some patchy fog or drizzle
will be possible as well. The moisture will also serve to keep
temperatures from cooling much overnight, and lows will be in the
50s areawide.

The front will lift back north on Wednesday, allowing showers to
once again develop, especially in the afternoon. Moist profiles and
poor lapse rates will limit instability, so not anticipating any
thunderstorms. With little in the way of sunshine, highs will be
cooler than today, especially in central/southern sections. Highs
will be in the mid 60s to around 70F. Like today, showers will wane
in the evening as we lose daytime heating. Lows will be similar to
tonight, perhaps a few degrees cooler.

&&

.SHORT TERM /THURSDAY NIGHT/...
As of 336 PM EDT Tuesday...On Thursday there will be pretty
pronounced upper level ridging that will stifle any showers that can
develop in weakly unstable environment. Overall the pattern should
support mainly dry weather between isolated, slow moving and light
showers. High temperatures should be a few to several degrees warmer
than on Wednesday with more low level dry air and lower cloud cover,
especially as one goes west. While winds will be light, there seems
to be some uncertainty as to the low level flow. The latest forecast
shows greater northerly flow down the Champlain Valley associated
with Canadian high pressure nosing southward, while a weak
southeasterly low level regime develops in eastern Vermont tied to
the closed low drifting over the western Atlantic. Overall, between
this low level flow and a ton of dry air aloft I don`t foresee any
significant shower activity despite the 30-50% PoPs during the day,
with greatest chances of rainfall generally in northern Vermont
shifting eastward with time. Any diurnally driven, light showers
should taper off quickly Thursday night with lack of any large scale
forcing and continued height rises. Would expect patchy fog could
develop overnight in the typical, localized valley locations with
light wind and probable clearing skies. Many areas should fully
decouple which will probably see lower temperatures than currently
indicated, but there is no threat of frost conditions with a
relatively mild air mass in place.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
As of 336 PM EDT Tuesday...The large scale weather pattern doesn`t
look to change much through early next week with a tendency towards
troughing. The resulting unsettled weather will remain largely
unimpactful due to deeper moisture being shunted south of the area
by convergent upper level flow. One notable shift in the forecast
has been towards warmer conditions on Friday as brief ridging builds
in. Probabilities of temperature exceeding 80 are now in the 35-45%
range in a large swath of the Champlain Valley, and 20-35% in some
other valley locations such as along the I-89 and I-91 corridors. So
mid to upper 70s look to be rather common with spot 80 degree
values, which would make it the warmest day so far this spring for
many spots. The NWS HeatRisk product suggests the warmth could
affect those who have extreme sensitivity to heat, especially given
we`ve been mostly on the cool side recent. However, with some clouds
and moderate humidity, it doesn`t look noteworthy as indicated by
the WBGT values below the elevated threshold.

A very weak cold front approaching from the west brings us higher
chances of showers in northern New York by Friday night spreading
areawide through Saturday. With no significant moisture or wind
fields, would think no more than a brief downpour with this system.
Moving into Sunday there remains some uncertainty with regards to
the upper level pattern but still favoring a trough with some shower
chances and lack of substantial instability. Most global model
clusters favor height rises with a warmer day on Monday compared to
Sunday, although about half of the 12Z EPS members do show a closed
low to our northwest that point to a possible change in the forecast
moving forward for early next week. More of the same for Tuesday so
NBM temperatures near to a bit above normal both days look
reasonable at this time along with largely 15 to 30% PoPs.

&&

.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
Through 06Z Thursday...It`s still pretty tricky whether or not
we`ll see some BR form overnight. Thus far it has not been very
consistent. Winds light and variable through about 12z. About
15z-16z, surface stationary front strengthens and numerous
showers will begin to develop with ceilings falling to 1000-2500
ft agl and visibilities 3 to 6SM in heavier showers. There
could be some improvement late in the day at KRUT and KMPV to
VFR. Winds will become south to southwest 4 to 8 knots, but
remain northeast at KMSS. Shower activity wanes after 22z.

Outlook...

Thursday: Mainly VFR, with local MVFR possible. Chance SHRA.
Thursday Night: VFR. NO SIG WX.
Friday: VFR. Slight chance SHRA.
Friday Night: VFR. Slight chance SHRA.
Saturday: Mainly VFR, with local MVFR possible. Chance SHRA.
Saturday Night: Mainly VFR, with local MVFR possible. Chance
SHRA.
Sunday: Mainly VFR, with local MVFR possible. Chance SHRA.

&&

.BTV WATCHES/WARNINGS/ADVISORIES...
VT...None.
NY...None.

&&

$$
SYNOPSIS...Hastings
NEAR TERM...Chai/Hastings/Neiles
SHORT TERM...Kutikoff
LONG TERM...Kutikoff
AVIATION...Neiles